2024/12/28 by Thiago L. M. Guedes, Guedes, Thiago L. M., Guillermo A. Mena Marugán +5 · 1 voice · 1 citation
Physics and Astronomy · #Black Holes and Theoretical Physics #FOS: Physical sciences #General Relativity and Quantum Cosmology (gr-qc) #Noncommutative and Quantum Gravity Theories #Quantum Physics (quant-ph) #gr-qc #quant-ph
paper · pdf · doi:10.48550/arxiv.2412.20257
openalex publication_date 2024/12/28 · arxiv published 2024/12/28 · openalex created_date 2025/10/10 · arxiv updated 2025/11/26 · openalex updated_date 2026/07/29
In loop quantum gravity (LQG), states of the gravitational field are represented by labeled graphs called spin networks. Their dynamics can be described by a Hamiltonian constraint, which acts on the spin network states modifying both spins and graphs. Fixed-graph approximations of the dynamics have been extensively studied, but its full graph-changing action so far remains elusive. The latter, alongside the solutions of its constraint, are arguably the missing features in canonical LQG to access phenomenology in all its richness. Here, we discuss a recently developed numerical tool that, for the first time, implements graph-changing dynamics via the Hamiltonian constraint. We explain how it is used to find new solutions to that constraint and to show that some quantum geometric observables behave differently than in the graph-preserving truncation. We also point out that these new numerical methods can find applications in other domains.